Add test fullness option for test.py when running examples

ns-3 tests using the TestSuite framework can be classified based on their typical runtime as being 'QUICK', 'EXTENSIVE', or 'TAKES_FOREVER'. This is the '-f' option to test.py. However, this does not extend to examples being run with test.py.

It would be helpful to extend test.py and examples_to_run.py to allow this test fullness as another option. I suggest, for instance, the 'examples/wireless/examples_to_run.py' could be extended as follows:

    ("wifi-hidden-terminal --wifiManager=Arf", "True", "True"),
    ("wifi-hidden-terminal --wifiManager=Aarf", "True", "True"),
    ("wifi-hidden-terminal --wifiManager=Aarfcd", "True", "True"),
    ("wifi-hidden-terminal --wifiManager=Onoe", "True", "True"),
    ("wifi-hidden-terminal --wifiManager=Amrr", "True", "True"),
    ("wifi-hidden-terminal --wifiManager=Minstrel", "True", "True"),
    ("wifi-hidden-terminal --wifiManager=Cara", "True", "True"),
    ("wifi-hidden-terminal --wifiManager=Rraa", "True", "True"),
    ("wifi-hidden-terminal --wifiManager=Rrpaa", "True", "True"),

changed to

    ("wifi-hidden-terminal --wifiManager=Arf", "True", "True", "EXTENSIVE"),
    ("wifi-hidden-terminal --wifiManager=Aarf", "True", "True", "EXTENSIVE"),
    ("wifi-hidden-terminal --wifiManager=Aarfcd", "True", "True", "EXTENSIVE"),
    ("wifi-hidden-terminal --wifiManager=Onoe", "True", "True", "EXTENSIVE"),
    ("wifi-hidden-terminal --wifiManager=Amrr", "True", "True", "EXTENSIVE"),
    ("wifi-hidden-terminal --wifiManager=Minstrel", "True", "True", "QUICK"),
    ("wifi-hidden-terminal --wifiManager=Cara", "True", "True", "EXTENSIVE"),
    ("wifi-hidden-terminal --wifiManager=Rraa", "True", "True", "EXTENSIVE"),
    ("wifi-hidden-terminal --wifiManager=Rrpaa", "True", "True", "EXTENSIVE"),

and for backward compatibility, this would also work as before (and default to QUICK):

    ("wifi-hidden-terminal --wifiManager=Minstrel", "True", "True"),